含水合物相变的油气井多相流动模型及应用研究

发布时间：2018-06-11 19:13

本文选题：天然气水合物 + 相变　；参考：《水动力学研究与进展(A辑)》2017年05期

【摘要】：深水钻井、测试过程中,井筒/管柱中易生成天然气水合物。该文研究了含水合物相变的井筒多相流动特征,建立了含水合物相变的井筒多相流动模型,提出了水合物生成区域的定量预测方法,研究了水合物生成与沉积特征,得到了水合物堵塞形成机制。水合物生成导致井筒环空内气体体积分数减小,使得气侵早期具有"隐蔽性";而水合物在井口附近分解会造成气体体积分数迅速增大,使得气侵后期具有"突发性",导致侵入气体处理难度大,井筒压力控制困难。应用该文建立的模型,可以定量预测深水气井测试作业中易发生水合物堵塞的高风险区。研究提出通过注入低浓度的抑制剂,延缓水合物堵塞的发生,可以有效克服传统防治方法过度使用抑制剂的不足。该文的工作可为水合物堵塞预测和防治工作提供参考。
[Abstract]:Natural gas hydrate is easily formed in wellbore / tubing during deep water drilling and testing. In this paper, the characteristics of multi-phase flow in wellbore with hydrate phase transition are studied, and the multi-phase flow model of well bore with hydrate phase transition is established, and the quantitative prediction method of hydrate formation region is put forward, and the formation and deposition characteristics of hydrate are studied. The formation mechanism of hydrate plugging is obtained. The formation of hydrates leads to the decrease of gas volume fraction in the annulus of wellbore, which makes the gas invasion early stage "concealed", and the decomposition of hydrate near the wellhead will cause the gas volume fraction to increase rapidly. As a result, it is difficult to deal with intrusive gas and to control wellbore pressure. The model established in this paper can be used to quantitatively predict the high risk areas where hydrate plugging is easy to occur in deep water gas well testing operations. It is suggested that by injecting low concentrations of inhibitors to delay the occurrence of hydrate blockage, the deficiency of overuse of inhibitors in traditional prevention and treatment methods can be effectively overcome. The work in this paper can provide reference for hydrate plugging prediction and prevention.
【作者单位】：中国石油大学(华东)石油工程学院;中国石油集团钻井工程技术研究院;
【基金】：国家重点基础研究发展计划(973计划,2015CB251200) 国家优秀青年科学基金(51622405) 国家重点研发计划(2016YFC0303408) 山东省自然科学基金(ZR2016EEM30)~~
【分类号】：TE28

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